The conciliation between different issues such as agriculture production, biodiversity conservation and water management remains unsolved in many places in the world. As a striking example, the wet grasslands of the Marais Poitevin region (France) presents many obstacles against the integration of these issues, especially in terms of public policy design. The socio-cultural situation in this region shows a high degree of political resistance and questions the relevancy of the current Agri-Environmental Schemes (AES) as an incentive for livestock farmers to adopt biodiversity friendly practices favoring the birds’ richness of the area. In this study, we explored the reasons for the poor effect of public policy using a two-fold approach based on ethnographic fieldwork and a role-playing game experiment. The ethnographic fieldwork aimed at understanding the local context and daily lives of farmers and current AES’s difficulties while the observation of the role-playing game session allowed for the exploration of current and alternative policy scenarios. The game represents an archetypal wetland that simulates the grass regeneration, water flows through a canal system and a surrounding network of cultivated plots (wheat, corn, sunflower, alfalfa) and pasture areas. The game is designed for eight players who embody their role in real life, i.e. water managers, biodiversity managers and farmers. The behaviors of the players during the session were observed and analyzed through semantic analysis. The game was structured around two scenarios to allow participants to explore, test and compare the current individual action-oriented AES with alternative collective public policy instruments. Such comparison brings new insights for public policy design. It also highlights the topic of integrated environmental management and questions the relevancy of participatory approaches in striving to resolve contradiction/dilemmas in environmental development.